Influence of water-permeable weed control sheets on additional radioactive cesium contamination of Shiitake (Lentinula edodes) bed logs in open-field cultivation

Abstract

The influence of water-permeable weed control sheets (WCS; a kind of weed control sheet) on additional contamination was investigated to control mud splashing on bed logs and the migration of radioactive Cs from the A0 and A layers. In a long-term study conducted 3 years after the Fukushima Daiichi nuclear accident, the concentration of radioactive Cs in the fruit-bodies and bed logs increased with the installation of WCS when compared to the untreated area. It was also suggested that the radioactive Cs that was absorbed from the lower part of the bed log was subsequently transferred to the upper part of the bed log and the side log. On the other hand, in a short-term follow-up study conducted 6 years after the nuclear accident, no additional contamination due to the installation of the WCS was observed. In the case of long-term cultivation, it is necessary to consider a different method using materials that selectively fix radioactive Cs in the soil and do not easily release it, rather than laying WCS.